Hardy mums are great for fall.
Hardy mums make a great addition to the fall garden, said a University of Illinois Extension horticulture educator.
"For some people, hardy mums are a necessary component of fall beauty," said Matt Kostelnick. "As they name suggests, they are very hardy and tolerate the dipping temperatures of cold autumn nights, unlike many other plants in the garden."
Mum, he added, is short for chrysanthemum and most gardeners are familiar with two types.
"One of those is the more flashy chrysanthemums bought at a floral shop either potted or sold as a cut flower," he said. "These are usually sold for floral purposes--not gardening. Their blooms tend to be very flashy and elaborate and the plants are sometimes referred to as 'florist chrysanthemums.' They don't over-winter in Illinois because they don't establish strong underground shoots."
The other chrysanthemums are the ones seen blooming in September, October, and sometimes as late as November. These hardy mums are grown as perennials in northern Illinois.
"Hardy mums can over-winter in northern Illinois because they do establish a strong underground shoot system," said Kostelnick. "In September, these plants set many flower buds and explode with blooms shortly thereafter."
Hardy mums are perennial in zones 5 to 9. The plants have many branches and can get quite large to appear almost shrub-like. Staking is often necessary for hardy mums that get too tall.
"These plants are available in a wide array of colors," he noted. "There are also many different flower-bloom types, including the very common pompoms, anemone, cushion, spider, quill, and daisy petals."
Planting hardy mums is similar to planting other plants. They can be planted in the spring or the fall.
"Try to plant hardy mums in full sun and away from street lights," he said. "Make sure that the hardy mums are suited to your zone. Some varieties are not hardy enough for northern Illinois. If planting hardy mums in the fall, plant at least six weeks before blooming to allow the plant to get established."
Mums are photoperiodic, which means they only bloom under certain lighting conditions. The plants require regular feeding due to their heavy blooming and also need adequate drainage.
"Discontinue fertilizing hardy mums in July," he noted. "Pinching stems encourages lateral growth and more numerous blooms. Pinching should be done in early to mid-summer. Flower buds can also be pinched as these are one of the most interesting and easiest plants to dis-bud.
"Mums do not need to be cut back after they have finished blooming in the fall. Instead, it is best to mulch the hardy mums with about six inches of mulch, such as pine needles or straw."